U.S. Drought Monitor Report for the Week Ending April 9 (Text)

April 11 (Bloomberg) -- Following is the text of the weekly
U.S. Drought Monitor as released by the National Drought
Mitigation Center in Lincoln, Nebraska:

Weather Summary: An active weather pattern, with several fronts
and storm systems traversing the lower 48 States, brought
welcome precipitation to much of the Nation, and particularly
the Plains. Decent precipitation (2 to 6 inches) returned to the
Northwest, with 1-2 inches as far south as central California
and the Sierra Nevada. Two separate storm systems, one in the
Midwest and one in the South, dropped light to moderate
precipitation on both areas earlier in the week. As the period
ended, a potent storm system located over the central Rockies
had already produced beneficial precipitation in parts of the
north-central Plains and western Corn Belt, with more rain and
severe weather possible for the eastern half of the U.S. during
the next few days. Unfortunately, little or no precipitation
fell on the Southwest, northern Plains, and Northeast, although
the latter area was expecting precipitation this week. After a
cold start to the period in the East and a mild one in the West,
temperatures began to moderate as the week ended. In Alaska, dry
and cold conditions enveloped the state except the southeastern
Panhandle, while Hawaii was mostly dry with some light windward
showers. Puerto Rico experienced scattered light showers during
the week.
The Northeast: With another week of little or no precipitation
(less than 0.5 inches), deficits accumulated during the past 90-
(2 to 4 inches) to 180-days (4 to 8 inches) continued to grow.
However, with temperatures averaging 2 to 4 degrees F below
normal, the growing season not yet started, snow still covering
parts of western New England, and most streams running near
normal, only a slight expansion of D0 was added where the
deficits were the greatest. This included western New York,
along the Vermont and New Hampshire border, and in central
Pennsylvania. The latter state will be closely monitored as USGS
stream flows have dropped below the tenth percentile. Deficits
also existed in Maine, but with much of this state still snow
covered, soil moisture will be assessed once the snow melts and
the ground thaws.
The Southeast: Much of this region received light to moderate
precipitation (0.5 to 1.5 inches), with a few areas (southern
sections of Louisiana, Mississippi, Alabama, and Florida)
recording over 2 inches of rain. With the wet pattern continuing
across Georgia since late January, additional removal of D1 and
D0 were made in central and eastern sections as 3-, 6-, and 12-
month surpluses were common in these areas. The April 9
NASS/USDA statewide topsoil (subsoil) moisture for Georgia was
rated 2 percent (7 percent) very short to short, 67 percent (71
percent) adequate, and 31 percent (22 percent) surplus. In
addition, stream flows, soil moisture models, CMI and PDI, and
SPI indices were all near normal to moist. Where medium- to
long-term deficiencies persisted, D0 and D1 remained, mainly in
east-central and coastal Georgia. Farther north, where 3-month
totals have been lower than Georgia, conditions were unchanged.
In Florida, extreme southern sections measured 2 to 3 inches of
rain, improving conditions by one category. In central and
northern Florida, 0.5 to 1.5 inches of rain were not enough to
make a significant dent in the 60- (3 to 6 inches) to 90-day (5
to 10 inches) departures, hence no improvement was made. USGS
stream flows remained below the tenth percentile in north-
central Florida. Farther west, heavy rains (more than 2 inches)
along the Gulf Coast erased abnormal dryness in parts of
southeastern Louisiana and southern Mississippi; however,
lighter rains (0.5 inches) in southern Alabama increased short-
term deficits, and D0 was expanded slightly eastward.
The Midwest: Light to moderate precipitation (0.5 to 1.5
inches), with pockets of heavier amounts (more than 2 inches),
fell across the western Corn Belt, providing some relief in
areas where there was no snow cover and the soil had thawed. To
back this, NWS frost tubes showed that the last of the frozen
soils in northern and central Iowa had thawed, and that some
farm tiles were running in eastern Iowa and northern Illinois,
indicating more subsoil moisture than previously thought. Many
USGS stream flows were in the upper 75th percentile.
Accordingly, improvements included the removal of D0 in eastern
Iowa, northern Illinois, and southern Wisconsin, D1 to D0 in
east-central Iowa, and some slight improvement of D2 to D1 in
central Iowa. In Missouri, the eastern edge of the D0 and D1
areas were slightly edged westward in response to 1 to 1.5
inches of rain and declining deficits. In contrast, soils north
of this region still had some ice in lower soil layers, and snow
remained on the ground in most of North Dakota and the northern
halves of Minnesota and Wisconsin. The southern third of
Minnesota was thawed to a depth of 12 inches, and will be
reassessed next week to determine soil moisture infiltration
amounts. Therefore, no changes were made to the upper Midwest
this week. For Nebraska improvements, please refer to The Plains
narrative.
Lower Mississippi Valley/Delta region: Two bands of heavy rain
(more than 2 inches) fell across the Delta, but in-between the
rain, little or no precipitation fell. In central Arkansas, 1.5
to 2.5 inches of rain (and more extending into Oklahoma) was
enough to reduce D0 and D1 by a category as 60- and 90-day small
deficits shrunk or were eliminated. Another band of heavy rain
fell along the Gulf Coast, easing drought in southeastern Texas
and extreme southeastern Louisiana. In-between the bands, only
0.5 to 1 inch fell on northwestern Louisiana and southwestern
Arkansas, maintaining D0 and D1.
The Plains: Beneficial, soaking rains finally fell on badly-
needed D2, D3, and D4 drought areas of hard-hit Texas, Oklahoma,
and Nebraska, with more falling after the 12 GMT Tuesday cutoff.
In Texas, 1 to 3 inches of rain was measured in north-central,
central, and southeastern Texas, providing a one category
improvement many areas. Unfortunately, little or no rain was
observed in western and extreme southern Texas, and some
degradation was made. In Oklahoma, a large band of heavy rain (2
to 5 inches) fell from central to southeastern parts of the
state, resulting in a one-category improvement. Most other areas
of the state received enough precipitation (0.5 to 1.5 inches)
to maintain conditions. Kansas was unfortunately left out of the
heavy rains, with most stations reporting under 0.5 inches. In
extreme northeastern Kansas, however, a small band of heavier
rain (1.5 to 2.5 inches) was enough to diminish deficits and
ease drought from D2 to D1.
Farther north, long overdue widespread and heavy rains finally
fell on much of north-central Plains, especially from the
southwestern Nebraska northeastward into southeastern South
Dakota. Most locations reported 1.5 to 3 inches of rain, and a
significant number of them likely received their greatest 24-
hour totals in the past 12 months. According to the Nebraska
State Climatologist Al Dutcher, all soil moisture sites in this
area have hit 25 percent for the 4 foot layer, and 20 percent
for the top 5 five foot. By next week it will become apparent
how deep the moisture made it into the profile. Based upon past
experiences, it is likely that field capacity will be reached in
the top 2 feet of the profile at most locations. But due to the
prolonged and severe drought, there is no deep moisture, but
moisture is available to support planting and early emergence.
Even with the April 9 rains, 12-month deficits still stood at:
10.59 inches at North Platte; 9.31 inches at Valentine; 16.59
inches at Broken Bow; and 6.55 inches at Imperial. And it will
take substantial additional moisture to improve drought
conditions further. Some reanalysis may occur next week as the
full extent of the precipitation associated with this event can
be examined. This event was a good start to the northern and
central Plains rainy season which normally occurs from April
into August. Similarly, some improvements were made farther
north in western South Dakota and eastern Montana as 0.5 to 1.5
inches of precipitation reduced deficiencies. This area will
also be reassessed next week as additional precipitation fell
after the 12 GMT Tuesday cutoff. And lastly in North Dakota,
snow covered ground and frozen soils meant status-quo for this
state.
The Rockies and Intermountain West: Light to moderate
precipitation (0.5 to 2 inches) fell on the northern and central
Rockies and Intermountain West, with little to no precipitation
measured in southern sections. Temperatures averaged above
normal throughout the region. In general, enough precipitation
fell to keep conditions status-quo, with a few exceptions. In
northeastern Utah, the Uinta Mountains received between 1 to 2
inches liquid equivalent, which was enough to improve from D2 to
D1. In southwestern Montana, 90-day subnormal precipitation
warranted the expansion of D1 and D2, with WYTD basin average
precipitation declining to 87 percent of normal and SWC at 85
percent of normal. Elsewhere, conditions remained the same, with
the exception of modifying the Impact lines to better reflect
the short-term dryness in the Far West and more medium-term
impacts (both short and long term) elsewhere.
The Far West and Southwest: Moderate to heavy rains (2 to 6
inches) fell west of the Cascades, from northern California
northward to the Canadian border. In the Sierra Nevada, 1 to 2.5
inches of precipitation occurred, but the Water Year-to-Date
(WYTD) average basin precipitation was still between 74 to 86
percent of normal, and the April 9 basin average snow water
content (SWC) between 37 to 49 percent of normal. Values were
better farther north in southern Oregon, with the southern
Cascades WYTD precipitation close to normal, and SWC between 63
to 74 percent of normal. With the heavy rains, D0 was removed
from much of southwestern Oregon and extreme northwestern
California, although some short-term deficits still remain due
to a dry January-March. However, since October 1, WYTD
precipitation is close to normal thanks to a very wet November
and December. Recent and WYTD precipitation was also enough to
make improvements in northwestern Nevada/ northeastern
California/southern Oregon (D2 to D1), and D0 removal in
northeastern Oregon.
Farther south, little or no precipitation and warm weather aided
deteriorating conditions in parts of the Southwest. In Arizona
and New Mexico, growing deficits in southwestern, southeastern,
and northeastern Arizona, and central New Mexico expanded D1-D3
drought. Since early October, precipitation has been less than
half of normal in eastern Arizona and much of New Mexico, and
the same hold true at 12-months. As a result, drought worsened
in Yavapai and Maricopa Counties in southwestern Arizona, and
most of southeastern Arizona was degraded to D2. D3 was expanded
into northeastern Arizona (Apache County), and increased in size
in western and southern New Mexico. Amazingly, central Arizona
was close to normal as the WYTD basin precipitation was between
85 to 97 percent of normal. Unfortunately, reservoir storage as
of April 1 was below average in Arizona, New Mexico, and Nevada.
Hawaii, Alaska, and Puerto Rico: In Hawaii, although most
locations received little or no rain during the week (except for
0.5 to 1 inches on windward sites on Oahu, Maui, and the Big
Island), solid March rainfall (150 to 200 percent of normal) on
northeastern Kauai eliminated the D0 there. On Maui and the Big
Island, the windward slopes have been unseasonably dry recently,
thus D0 was added to the rest of those islands. On Molokai, the
current D2 area for low reservoir levels at Kualapuu Reservoir
was eased from 30 percent to 20 percent cutback, but since this
is still a significant reduction, D2 remained. Although the
level is 4 to 5 feet higher than a year ago, it’s currently at
21 feet, and the maximum capacity is 51 feet. In Alaska, cold
and dry weather, except in the southeastern Panhandle (2 to 3
inches), maintained conditions there. In Puerto Rico, widespread
light showers (0.5 to 2 inches) were enough to maintain
conditions but not improve them.
Looking Ahead: The next 5 days (April 11-15) are expected to be
wet across much of the eastern half of the U.S., with the
greatest totals (more than 2 inches) forecast for the South and
lower Great Lakes region. Light to moderate precipitation should
fall along the Pacific Northwest Coast and in the northern
Rockies. Much of the Southwest and High Plains will be dry.
Temperatures should average below normal across the northern
third of the U.S., especially in the northern Plains and upper
Midwest, while above-normal readings are expected in the
Southwest and Southeast.
For the ensuing 5 days (April 16-20), the odds favor above-
normal precipitation in the eastern half of the Nation and the
north-central Plains. Drier-than-normal weather is forecast for
the West, Southwest, southern Florida, and Alaska. Temperatures
are expected to be similar to the Day 1-5 forecast, with odds
favoring below-normal readings in the North-Central States, and
above-normal temperatures in California and the eastern Gulf and
southern Atlantic States.